Battery

The battery design addresses unstable electrical connections by using a conductive plate with a protruding support and elastic insulator to ensure stable contact with the power generation element, effectively maintaining electrical connections despite manufacturing variations and vibrations.

JP7765635B2Active Publication Date: 2025-11-06MAXELL LTD
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Patent Information

Application Number
JP2024528985
Authority / Receiving Office
JP · JP
Patent Type
Patents
Current Assignee / Owner
Priority Date
2022-06-16
Filing Date
2023-06-16
Publication Date
2025-11-06
Estimated Expiration
2043-06-16

AI Technical Summary

Technical Problem

Existing battery designs face issues with unstable electrical connections due to displacement or deformation of the conductive sheets, particularly when manufacturing variations and vibrations, which are not adequately addressed in existing technologies, and the curved surface of a leaf spring that is curved significantly, and the curved surface of a leaf spring that is curved toward the electrochemical element, and the curved surface of a leaf spring that is curved toward the electrochemical element, causing poor electrical contact.

Method used

A battery design with a conductive plate having a support portion that protrudes toward the sidewall of the container, supported by an elastic insulator, maintains stable contact with the power generation element, absorbing thickness variations and preventing displacement, ensuring a good electrical connection.

Benefits of technology

The design maintains stable electrical connections by supporting the conductive plate with a protrusion and using an elastic insulator, allowing the battery to absorb thickness discrepancies and maintain contact even under varying conditions.

✦ Generated by Eureka AI based on patent content.

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Abstract

Provided is a battery capable of maintaining a favorable electrical connection. A battery 1 is provided with: a case 10 including a concave container 11, which has a bottom section 111 and a side wall section 112, and a lid member 12 covering the opening of the concave container; a power generation element 20 accommodated in the case 10; a conductive plate 30 which is disposed between the power generation element 20 and the lid member 12 and is accommodated in the case 10; and an elastic insulator 40 which is disposed between the conductive plate 30 and the lid member 12 and is accommodated in the case 10. The conductive plate 30 has a support part 32 for, when accommodated in the case 10, supporting the conductive plate in a position corresponding to the top end surface of the side wall section 112 of the concave container 11. The support part 32 is a protruding part which causes a portion of the conductive plate 30 to protrude toward the upper end face of the side wall section 112 of the concave container 11. The elastic insulator 40, when accommodated in the case 10, presses the conductive plate 30 toward the power generation element 20.
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Description

[Technical Field]

[0001] The present disclosure relates to batteries. [Background technology]

[0002] BACKGROUND ART Various types of batteries have been disclosed in the past, in which a power generating element is housed in an internal space formed by a recessed container and a lid member that covers the opening of the recessed container.

[0003] Japanese Patent Laid-Open Publication No. 2012-69508 (Patent Document 1) discloses an electrochemical cell with stable electrochemical characteristics. The electrochemical cell has a sealed container. The sealed container is made of a base member and a lid member. A storage space for storing an electrochemical element is formed between the two members. An elastic member is disposed between the lid member and the electrochemical element to press against the electrochemical element. Patent Document 1 discloses, as the elastic member, a leaf spring bent in a V-shape in cross section or a leaf spring curved toward the electrochemical element.

[0004] WO 2022 / 030424 (Patent Document 2) discloses a battery package and a battery module. The battery module includes an insulating substrate including a first surface and a recess that opens onto the first surface and accommodates a battery, a frame that surrounds the recess on the first surface, a second electrode that is positioned between the frame and the recess, a conductive sheet that is electrically connected to the second electrode and extends from the first surface to the opening of the recess, a lid that covers the frame, and a spacer that is positioned between the lid and the conductive sheet and in contact with the lid and the conductive sheet.

[0005] Japanese Patent Laid-Open Publication No. 2006-12792 (Patent Document 3) discloses a battery case and a battery. The battery case includes a ceramic base body with a recess formed in the center of its top surface, and a lid body whose outer periphery is joined to the base body so as to cover the recess. The battery includes a battery case and a power generating element housed in the battery case. The lid body has a protrusion at its center that protrudes entirely toward the recess, and a curved portion is provided between the protrusion and the outer periphery. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Japanese Patent Application Laid-Open No. 2012-69508 [Patent Document 2] International Publication No. 2022 / 030424 [Patent Document 3] Japanese Patent Application Laid-Open No. 2006-12792 Summary of the Invention

[0007] However, the V-shaped bent leaf spring in the electrochemical cell of Patent Document 1 does not have stable contact with the electrochemical element, and there is a risk of it becoming displaced due to vibration, etc. Furthermore, the curved surface of a leaf spring that is curved significantly is in contact with the electrochemical element, so there is a risk of the electrical connection being unstable.

[0008] Furthermore, in the battery module of Patent Document 2, since the conductive sheet is flat and plate-shaped, when the spacer presses the center of the conductive sheet, the edge of the conductive sheet tends to lift up, with the edge of the insulating substrate on the recess side of the first surface acting as a fulcrum. Therefore, if the thickness of the power generating element becomes thinner than the design value due to manufacturing variations in the battery module, deformation of the conductive sheet increases, which may cause the bond between the conductive sheet and the conductive bonding material to become unstable and make it impossible to maintain a good electrical connection.

[0009] Furthermore, in the battery of Patent Document 3, the protruding portion of the lid body is brought into contact with the negative electrode. Therefore, if the thickness of the power generating element becomes thinner than the design value due to manufacturing variations, the lid body will not come into contact with the power generating element, which may result in poor electrical connection.

[0010] Therefore, an object of the present disclosure is to provide a battery that can maintain good electrical connection.

[0011] In order to solve the above problems, the present disclosure is configured as follows. Specifically, the battery according to the present disclosure includes a case having a recessed container with a bottom and sidewalls and a lid covering the opening of the recessed container; a laminate including a first electrode layer, a second electrode layer, and a solid electrolyte layer disposed between the first and second electrode layers; a power generation element housed in the case; a conductive plate disposed between the power generation element and the lid; and an elastic insulator disposed between the conductive plate and the lid. The conductive plate has a support portion for supporting the conductive plate at a position corresponding to the upper end surface of the sidewall of the recessed container. The support portion is a protrusion that protrudes a portion of the conductive plate toward the upper end surface of the sidewall of the recessed container. The elastic insulator presses the conductive plate toward the power generation element when housed in the case.

[0012] The battery according to the present disclosure can maintain good electrical connection. [Brief explanation of the drawings]

[0013] [Figure 1] FIG. 1 is a cross-sectional view showing a battery according to a first embodiment. [Figure 2] FIG. 2 is a plan view showing the battery shown in FIG. 1 (excluding the cover, conductive plate, and elastic insulator). [Figure 3] FIG. 3 is a plan view showing the conductive plates of the battery shown in FIG. [Figure 4] FIG. 4 is a cross-sectional view showing a battery according to the second embodiment. [Figure 5] FIG. 5 is a cross-sectional view showing a battery according to a third embodiment. [Figure 6] FIG. 6 is a cross-sectional view showing a battery according to the third modification. DETAILED DESCRIPTION OF THE INVENTION

[0014] (Configuration 1) A battery according to an embodiment of the present disclosure includes a case having a recessed container with a bottom and sidewalls and a lid covering the opening of the recessed container, a laminate including a first electrode layer, a second electrode layer, and a solid electrolyte layer disposed between the first and second electrode layers, a power generation element housed in the case, a conductive plate disposed between the power generation element and the lid, and an elastic insulator disposed between the conductive plate and the lid. The conductive plate has a support portion for supporting the conductive plate at a position corresponding to the upper end surface of the sidewall of the recessed container. The support portion is a protrusion that protrudes a portion of the conductive plate toward the upper end surface of the sidewall of the recessed container. The elastic insulator presses the conductive plate toward the power generation element when housed in the case.

[0015] In this way, the conductive plate presses the power generating element toward the bottom of the concave container, allowing the conductive plate to make more stable contact with the power generating element even when the volume of the power generating element changes. This prevents the conductive plate from shifting position due to vibration or other factors, allowing the battery to maintain a good electrical connection. Furthermore, by supporting the conductive plate with its support portion, i.e., the protrusion, the conductive plate does not contact the inner peripheral edge of the side wall of the concave container. This prevents the electrical connection from being disrupted due to deformation of the conductive plate. Furthermore, because the conductive plate is pressed by a compressible elastic insulator, variations in the thickness of the power generating element can be absorbed by changes in the amount of deformation of the elastic insulator, achieving a good electrical connection.

[0016] (Configuration 2) In the battery of Configuration 1, the conductive plate may have at least two or more support portions, which allows the conductive plate to be more stably supported on the upper end surface of the side wall portion, suppresses misalignment of the conductive plate, and maintains better electrical connection.

[0017] (Configuration 3) In the battery of Configuration 1 or Configuration 2, the conductive plate may have a flat surface facing the power generating element.

[0018] (Configuration 4) In the battery of any one of Configurations 1 to 3, the elastic insulator may be made of rubber.

[0019] (Configuration 5) In any of the batteries of Configurations 1 to 4, the battery may further include a conductive sheet disposed between the conductive plate and the power-generating element to reduce contact resistance. In particular, by disposing a conductive sheet that is more flexible, i.e., more easily deformable, than the conductive plate, it is possible to maintain better electrical connection even if the volume of the power-generating element changes.

[0020] (Configuration 6) Another embodiment of the battery includes a case having a recessed container with a bottom and sidewalls and a lid covering the opening of the recessed container, a flat battery housed in the case, a conductive plate disposed between the flat battery and the lid, and an elastic insulator disposed between the conductive plate and the lid. The conductive plate has a support portion for supporting the conductive plate at a position corresponding to the upper end surface of the sidewall of the recessed container. The support portion is a protrusion that protrudes a portion of the conductive plate toward the upper end surface of the sidewall of the recessed container. The elastic insulator presses the conductive plate toward the flat battery when housed in the case. In this way, good electrical connection can be maintained even when a flat battery is housed in the internal space of the case.

[0021] (Configuration 7) In the battery of configuration 6, the conductive plate may have a flat surface facing the flat battery.

[0022] The material of the concave container is not particularly limited, and various materials such as resin, glass (borosilicate glass, glass ceramics, etc.), metal, and ceramic can be exemplified. A composite material in which ceramic or glass powder is dispersed in resin may also be used. When the concave container is made of a metal material, it is desirable to coat the inner surface of the bottom and the inner circumferential surface of the side wall of the concave container with an insulating material such as a resin material or glass to ensure insulation between the concave container and the power generating element or between the concave container and the flat battery.

[0023] (First embodiment) The first embodiment of the present disclosure will be specifically described below with reference to Figures 1 to 3. First, as shown in Figure 1, a battery 1 is composed of a case 10, a power generating element 20 housed in the case 10, a conductive plate 30 housed in the case 10, and an elastic insulator 40 housed in the case 10.

[0024] The case 10 includes a concave container 11, a cover member 12, a connection terminal 13, and a connection terminal 14.

[0025] The recessed container 11 is made of ceramic. The recessed container 11 includes a rectangular bottom 111 and a rectangular tubular sidewall 112 that is formed continuously from the outer periphery of the bottom 111 and has a cylindrical space therein for accommodating the power generating element 20. The sidewall 112 extends substantially perpendicular to the bottom 111 in a vertical cross-sectional view. A conductor 113 is formed inside the bottom 111. The conductor 113 extends between the power generating element 20 and the bottom 111 so as to be conductively connected to the power generating element 20. A conductor 114 is formed inside the sidewall 112. As shown in FIGS. 1 and 2 , a portion of the conductor 114 is exposed at the upper end surface of the sidewall 112. As described below, the exposed surface of the conductor 114 at the upper end surface of the sidewall 112 is positioned to correspond to the support portion 32 formed on the conductive plate 30. A manufacturing method for the recessed container 11 will be described later. The recessed container 11 is not limited to being made of ceramic, but may be made of an insulating material such as synthetic resin. The recessed container 11 is not limited to being rectangular in plan view, but may be circular, elliptical, or polygonal. The internal space for accommodating the power generating element 20 is not limited to being cylindrical, but may be formed into a polygonal cylindrical shape such as a rectangular cylindrical shape depending on the shape of the power generating element 20. The conductor portion 114 may be formed on the inner surface of the side wall portion 112 rather than inside the side wall portion 112, and may further penetrate the inside of the bottom portion 111 to be electrically connected to the connection terminal 14. In this case, it is desirable to form an insulating layer between the outer peripheral surface of the power generating element 20 and the conductor portion 114, for example, on the inner surface of the conductor portion 114, so that the outer peripheral surface of the power generating element 20 and the conductor portion 114 do not come into contact with each other.

[0026] The lid member 12 is a rectangular metal thin plate that covers the opening of the recessed container 11. As shown in FIGS. 1 and 2 , the lid member 12 is joined (seam-welded) to the recessed container 11 by a rectangular frame-shaped seal ring 15 disposed between the lower surface of the outer peripheral edge of the lid member 12 and the upper end of the recessed container 11. This completely seals the interior space of the case 10. The interior space of the case 10 is preferably a vacuum atmosphere or an inert gas atmosphere such as nitrogen, taking into consideration the influence on the power generating element 20. Note that the lid member 12 is not limited to a metal thin plate as long as it can cover the opening of the recessed container 11. The shape of the lid member 12 is not limited to a rectangular shape, and can be variously changed to a circular shape, an elliptical shape, a polygonal shape, etc., depending on the shape of the recessed container 11 in a planar view. The lid member 12 may also have a shape other than a flat plate. Note that the lid member 12 may be bonded to the recessed container 11 with an adhesive, and the method for joining the lid member 12 to the recessed container 11 is not particularly limited.

[0027] The connection terminal 13 is disposed on the outer surface of the bottom 111 of the hollow container 11. The connection terminal 13 is electrically connected to an electrode layer 21 (described later) via a conductor 113. The electrode layer 21 functions as a positive electrode layer (described later). Therefore, the conductor 113 serves as a conductive path that connects the connection terminal 13 and the positive electrode layer, and the connection terminal 13 functions as a positive electrode terminal.

[0028] The connection terminal 14 is disposed on the outer surface of the bottom 111 of the recessed container 11, spaced apart from the connection terminal 13. The connection terminal 14 is electrically connected to the support portion 32 of the conductive plate 30 (described later) via the conductor portion 114. As described later, the conductive plate 30 is electrically connected to the electrode layer 22, which functions as a negative electrode layer. Therefore, the conductor portion 114 and the conductive plate 30 form a conductive path connecting the connection terminal 14 to the negative electrode layer, and the connection terminal 14 functions as a negative electrode terminal. The arrangement of the connection terminals 13 and 14 is not limited to the above. They may be disposed on the outer surface of the side wall portion 112 of the recessed container 11. Alternatively, the lid member 12 may function as the conductor portion 114, and the connection terminal 14 may be formed on the outer surface of the lid member 12. However, by arranging these two terminals at a certain distance on the outer surface of the bottom 111 of the recessed container 11, they can be mounted on the surface of a circuit board.

[0029] Here, a method for manufacturing the concave container 11 will be described. First, a metal paste is printed onto a ceramic green sheet to form a printed pattern that will become the conductor portions 113 and 114. Next, a plurality of green sheets on which these printed patterns have been formed are stacked, thereby producing a concave container 11 that has the conductor portions 113 and 114 inside and the above-mentioned support portion 115 on the inner surface of the side wall portion 112. Note that the connection terminals 13 and 14 can also be formed by printing the metal paste pattern.

[0030] The power generating element 20 includes an electrode layer (positive electrode layer) 21, an electrode layer (negative electrode layer) 22, and a solid electrolyte layer 23. The solid electrolyte layer 23 is disposed between the electrode layers 21 and 22. The power generating element 20 is formed in a cylindrical shape. The electrode layer 21, the solid electrolyte layer 23, and the electrode layer 22 are stacked in this order from the bottom 111 side of the recessed container 11 (the lower side in the figure). That is, the power generating element 20 is housed in the internal space of the case 10 so that the lower surface of the electrode layer 21 faces the inner surface of the bottom 111 of the recessed container 11. The shape of the power generating element 20 is not limited to a cylindrical shape, and various other shapes such as a rectangular parallelepiped shape or a polygonal prism shape can be used.

[0031] The electrode layer 21 is a positive electrode pellet obtained by placing a positive electrode mixture containing lithium cobalt oxide, a sulfide-based solid electrolyte, and graphene as a conductive additive in a mass ratio of 65:30:5 as a positive electrode active material used in lithium-ion secondary batteries in a mold with a diameter of 7.45 mm and forming it into a cylindrical shape. The positive electrode active material of the electrode layer 21 is not particularly limited as long as it can function as the positive electrode layer of the power generation element 20. For example, the positive electrode active material of the electrode layer 21 may be lithium nickel oxide, lithium manganese oxide, lithium nickel cobalt manganese composite oxide, olivine-type composite oxide, or an appropriate mixture of these. The size and shape of the electrode layer 231 are not limited to a cylindrical shape and can be variously changed depending on the size and shape of the battery 1.

[0032] The electrode layer 22 is made of LTO (Li4Ti5O 12 The negative electrode pellet is a cylindrically shaped negative electrode mixture containing a 50:40:10 weight ratio of lithium titanium dioxide (lithium titanate), a sulfide-based solid electrolyte, and graphene. The negative electrode active material of the electrode layer 22 is not particularly limited as long as it can function as the negative electrode layer of the power generating element 20. For example, it may be metallic lithium, a lithium alloy, a carbon material such as graphite or low-crystalline carbon, or an oxide such as SiO, or an appropriate mixture of these. The size and shape of the electrode layer 22 are not limited to a cylindrical shape and can be variously changed depending on the size and shape of the battery 1.

[0033] The solid electrolyte layer 23 is a sulfide-based solid electrolyte formed into a cylindrical shape. The solid electrolytes contained in the electrode layers 21, 22, and 23 are not particularly limited, but sulfide-based solid electrolytes, particularly argyrodite-type sulfide-based solid electrolytes, are preferred in terms of ion conductivity. When using a sulfide-based solid electrolyte, it is preferable to coat the surface of the positive electrode active material with a lithium ion conductive material such as niobium oxide to prevent reaction with the positive electrode active material. The solid electrolytes contained in the solid electrolyte layer 23, the electrode layers 21, and the electrode layers 22 may be hydride-based solid electrolytes, oxide-based solid electrolytes, or the like. The size and shape of the solid electrolyte layer 23 are not limited to a cylindrical shape and can be varied depending on the size and shape of the battery 1.

[0034] As shown in FIGS. 1 and 3 , the conductive plate 30 is a metal plate member having a rectangular shape in a plan view and installed in the opening of the recessed container 11 of the case 10. The conductive plate 30 has a flat portion 31 and support portions 32 for supporting the conductive plate 30 on the upper end surface of the side wall portion 112 of the recessed container 11. The lower surface of the flat portion 31 faces the power generating element 20 and contacts the upper surface of the electrode layer 22 (described later). Two or more support portions 32 are provided so that the conductive plate 30 can be supported on the upper end surface of the side wall portion 112. This allows the conductive plate 30 to be more stably supported on the upper end surface of the side wall portion 112. From the perspective of stably supporting the conductive plate 30, it is preferable to provide three or more support portions 32 at equal intervals along the edge of the conductive plate 30. In this embodiment, the conductive plate 30 has four support portions 32 at its four corners. The support portions 32 are protrusions that protrude from the flat portion 31 toward the upper end surface of the side wall portion 112. The protruding portions are continuous with the flat portion 31. The support portions 32 support the conductive plate 30 so that the flat portion 31 is positioned between the upper end surface of the side wall portion 112 and the lid member 12. That is, the flat portion 31 is supported by the support portions 32 formed by the protruding portions and is therefore suspended above the upper end surface of the side wall portion 112. This makes the flat portion 31 more likely to bend toward the power generating element 20 when pressed toward the power generating element 20 by an elastic insulator 40 (described later). At least a portion of the support portions 32 is in contact with the conductor portion 114 exposed at the upper end surface of the side wall portion 112. As a result, the conductive plate 30 functions as a current collector and also forms part of a conductive path that electrically connects the electrode layer 22 and the connection terminal 14. For example, if the entire conductive plate 30 is flat, i.e., if the conductive plate 30 is flat, pressing the center of the conductive plate 30 toward the power-generating element 20 causes the inner edge of the upper end surface of the side wall 112 to serve as a fulcrum, causing the outer edge of the conductive plate 30 to lift off the upper end surface of the side wall 112. This can easily cause a problem in that it becomes difficult to maintain a good conductive connection between the conductive plate 30 and the conductor 114. In the battery 1, by configuring the support portion 32 as a protrusion, even when the center of the conductive plate 30 is pressed toward the power-generating element 20, the conductive plate 30 does not come into contact with the inner edge of the upper end surface of the side wall 112, maintaining a good conductive connection between the support portion 32 and the conductor 114, thereby stabilizing the electrical connection. The conductive plate 30 covers the opening of the recessed container 11.The area of ​​the conductive plate 30 in a plan view is larger than the opening area of ​​the recessed container 11. The number or positions of the support portions 32 and the number or positions of the exposed surfaces of the conductor portion 114 are not limited to these and may be any number that can support the conductive plate 30 and electrically connect the conductive plate 30 to the connection terminal 14. As shown in FIGS. 2 and 3 , of the support portions 32 provided at the four corners of the conductive plate 30, two support portions 32 contact the conductor portion 114, while the other two support portions 32 do not contact the conductor portion 114. In this manner, some of the multiple support portions 32 may contact the conductor portion 114. However, contacting two or more support portions 32 with the conductor portion 114 provides a more stable electrical connection.

[0035] The elastic insulator 40 is made of an insulating material. In this embodiment, the elastic insulator 40 is made of rubber. The insulating material is not limited to rubber and can be variously modified. The elastic insulator 40 is a circular sheet that conforms to the shape of the upper surface of the power generating element 20 in a planar view. The elastic insulator 40 is disposed between the flat portion 31 of the conductive plate 30 and the lid member 12. The elastic insulator 40 has a thickness greater than the gap between the flat portion 31 of the conductive plate 30, which is placed on the upper end surface of the side wall portion 112 via the support portion 32, and the lid member 12. In the assembly process of the battery 1, the power generating element 20 is accommodated in the recessed container 11, and then the conductive plate 30 is placed so that the flat portion 31 covers the power generating element 20. Thereafter, the elastic insulator 40 is placed on the surface opposite (upper side in the figure) of the flat portion 31 corresponding to the position of the power generating element 20. When the lid member 12 is closed, the elastic insulator 40 presses the conductive plate 30 against the power generating element 20. At this time, because the end of the conductive plate 30 is supported by the upper end surface of the sidewall portion 112, the portion of the flat portion 31 corresponding to the power generating element 20 bends slightly toward the power generating element 20. This allows the conductive plate 30 to appropriately press the power generating element 20 toward the bottom side of the recessed container 11, suppressing misalignment of the conductive plate 30 and stabilizing the electrical connection. Furthermore, since the flat portion 31 presses the power generating element 20 over a wide area, damage to the electrode layer 22 when the power generating element 20 expands can be suppressed. The wider conductive connection area maintains a better electrical connection. Furthermore, the elastic insulator 40 is made of a compressible insulating material. Therefore, when the elastic insulator 40 presses the conductive plate 30, the change in the amount of deformation of the elastic insulator 40 can absorb any thickness discrepancy in the power generating element 20, thereby achieving a good electrical connection.

[0036] (Second embodiment) Next, the battery 1 of the second embodiment will be specifically described with reference to Fig. 4. In the battery 1 of this embodiment, the description of the same configuration as the battery 1 of the first embodiment will basically be omitted, and only the configuration different from the battery 1 of the first embodiment will be described.

[0037] The battery 1 of this embodiment has a conductive sheet 50 between the electrode layer 22 and the conductive plate 30. In this embodiment, the conductive sheet 50 is a conductive sheet made of expanded graphite, i.e., a graphite sheet. The graphite sheet is manufactured as follows. First, particles of acid-treated graphite, which is natural graphite that has been treated with an acid, are heated. The acid present between the layers of the acid-treated graphite then vaporizes and foams, causing it to expand. This expanded graphite (expanded graphite) is molded into a felt shape and then rolled using a rolling mill to form a sheet. The conductive sheet 50 is manufactured by cutting out a circular shape from the expanded graphite sheet. As described above, expanded graphite is formed when the acid vaporizes and the acid-treated graphite foams. Therefore, the graphite sheet is formed into a porous shape. Therefore, the graphite sheet has the conductivity inherent in graphite itself as well as flexibility not found in conventional graphite products. However, the method for manufacturing the graphite sheet is not limited to this, and the graphite sheet may be made of a material other than expanded graphite, and the graphite sheet may be manufactured by any method.

[0038] The apparent density of the graphite sheet is 0.3 g / cm 3 More preferably, 0.7 g / cm 3 It is preferable that the apparent density of the graphite sheet is set to 100% or more. If the apparent density of the graphite sheet is too low, the graphite sheet will be easily damaged. Note that the apparent density is not limited to graphite sheets, but can also be applied to conductive sheets 50 made of other materials, such as conductive tape.

[0039] The thickness of the graphite sheet is preferably 0.05 mm or more, more preferably 0.07 mm or more, and is preferably 0.5 mm or less, more preferably 0.2 mm or less. If the graphite sheet is too thin, it becomes more susceptible to breakage, and if it is too thick, the graphite sheet narrows the internal space of case 10 that houses power generating element 20, reducing the volume (thickness) of power generating element 20 that can be housed therein. Note that the thickness of the graphite sheet is not limited to that of a graphite sheet, and it is also applicable to conductive sheet 50 formed from other materials, such as conductive tape.

[0040] By providing the conductive sheet 50, which is more flexible than the conductive plate, i.e., more easily deformable, the pressing force of the conductive plate 30 is transmitted more uniformly to the power generating element 20, preventing damage to the power generating element 20, and its excellent flexibility ensures stable electrical connection. Note that the conductive sheet 50 may be disposed between the electrode layer 21 and the bottom 111 of the recessed container 11, as shown in FIG. 4. This further prevents damage to the power generating element 20 and stabilizes the electrical connection.

[0041] (Third embodiment) Next, the battery 1 of the third embodiment will be specifically described with reference to Fig. 5. In the battery 1 of this embodiment, the description of the same configuration as the battery 1 of the first and second embodiments will basically be omitted, and only the configuration different from the battery 1 of the first and second embodiments will be described.

[0042] The battery 1 of this embodiment houses a flat battery 60 in the internal space of the case 10. As shown in Fig. 5, the flat battery 60 has an outer can 61, a sealing can 62, the above-mentioned power generating element 20, and a gasket 63. The flat surface 31 of the conductive plate 30 faces the flat battery 60 and is in contact with a flat surface 621 of the sealing can 62, which will be described later.

[0043] The outer can 61 includes a circular flat portion 611 and a cylindrical side wall portion 612 formed continuously from the outer periphery of the flat portion 611. The cylindrical side wall portion 612 is provided so as to extend substantially perpendicular to the flat portion 611 in a vertical cross-sectional view. The outer can 61 is made of a metal material such as stainless steel.

[0044] The sealing can 62 has a circular flat portion 621 and a cylindrical peripheral wall portion 622 formed continuously from the outer periphery of the flat portion 621. The opening of the sealing can 62 faces the opening of the outer can 61. The sealing can 62 is made of a metal material such as stainless steel.

[0045] After the power generating element 20 is accommodated in the internal space of the outer can 61 and the sealing can 62, the outer can 61 and the sealing can 62 are crimped together with a gasket 63 interposed between the cylindrical side wall 612 of the outer can 61 and the peripheral wall 622 of the sealing can 62. More specifically, the outer can 61 and the sealing can 62 are arranged with their openings facing each other, the peripheral wall 622 of the sealing can 62 is inserted inside the cylindrical side wall 612 of the outer can 61, and then the outer can 61 and the sealing can 62 are crimped together with the gasket 63 interposed between the cylindrical side wall 612 and the peripheral wall 622. As a result, the internal space formed by the outer can 61 and the sealing can 62 is sealed. Note that the shapes of the outer can 61 and the sealing can 62 are not limited to being circular in plan view, and can be variously modified, such as elliptical or polygonal.

[0046] The gasket 63 is made of a resin material such as polyamide resin, polypropylene resin, or polyphenylene sulfide resin. The method for sealing the internal space formed by the outer can 61 and the sealed can 62 is not limited to crimping via the gasket 63, and other methods may be used. For example, the cylindrical side wall 612 of the outer can 61 and the peripheral wall 622 of the sealed can 62 may be joined and sealed using a heat-melting resin, adhesive, or the like.

[0047] In this way, even when flat batteries 60 are housed in the internal space of the case 10, good electrical connections can be maintained, similar to the battery 1 of the first embodiment described above.

[0048] In the battery 1 of this embodiment, although not specifically shown, the above-mentioned conductive sheet 50 may be disposed between the flat battery 60 and the conductive plate 30. The conductive sheet 50 may also be disposed between the flat battery 60 and the bottom 111 of the recessed container 11.

[0049] The flat battery 60 is not limited to an all-solid-state battery having a solid electrolyte layer, but may be any other flat-shaped battery such as a non-aqueous electrolyte battery.

[0050] (Variation 1) In the first to third embodiments described above, the electrode layer 21 functions as a positive electrode layer and the electrode layer 22 functions as a negative electrode layer, but the electrode layer 21 may function as a negative electrode layer and the electrode layer 22 may function as a positive electrode layer. In this case, the connection terminal 13 functions as a negative electrode terminal and the connection terminal 14 functions as a positive electrode terminal.

[0051] Furthermore, in the first to third embodiments described above, the battery 1 is configured to house one power generating element 20, but a bipolar battery 1 may be configured in which a plurality of power generating elements 20 are connected in series.

[0052] In the third embodiment described above, the flat battery 60 is housed in the internal space of the case 10 so that the outer can 61 and the bottom 111 of the recessed container 11 face each other, but the flat battery 60 may also be housed so that the sealing can 62 and the bottom 111 of the recessed container 11 face each other. That is, the flat battery 60 may be housed in the internal space of the case 10 in a state where the flat battery 60 shown in FIG. 5 is turned upside down. In this case, the flat surface 31 of the conductive plate 30 contacts the flat surface 611 of the outer can 61.

[0053] (Variation 2) In the first to third embodiments described above, the elastic insulator 40 may be made larger in the radial direction so that the elastic insulator 40 is also positioned between the support portion 32 of the conductive plate 30 and the lid member 12. In this case, the elastic insulator 40 directly presses the support portion 32 toward the upper end surface of the side wall portion 112 of the recessed container 11, making it easier to maintain a good conductive connection between the support portion 32 and the conductor portion 114.

[0054] (Variation 3) In the first to third embodiments described above, as shown in Fig. 6, a spring piece 33 may be provided that is cantilevered on the flat surface 31 of the conductive plate 30 and presses the power generating element 20 and the like toward the bottom 111 of the recessed container 11. By bringing the spring piece 33 into contact with the power generating element 20, the conductive sheet 50, or the flat surface 621 of the sealing can 62, a reduction in contact resistance can be expected compared to when the flat surface 31 is in contact. To prevent the tip of the spring piece 33 from damaging the power generating element 20 and the like, the tip of the spring piece 33 may be bent toward the flat surface 31, and the underside of the bent part may be brought into contact with the power generating element 20 and the like.

[0055] Although the embodiments have been described above, the present disclosure is not limited to the above-described embodiments, and various modifications are possible without departing from the spirit of the present disclosure. [Explanation of symbols]

[0056] 1 battery, 10 case, 11 concave container, 12 lid material, 13 connection terminal, 14 connection terminal, 15 seal ring, 111 bottom, 112 side wall, 113 conductor portion, 114 conductor portion, 20 power generating element, 30 conductive plate, 31 flat portion, 32 support portion (protruding portion), 33 spring piece, 40 elastic insulator, 50 conductive sheet, 60 flat battery, 61 outer can, 611 flat portion, 62 sealed can, 621 flat portion, 63 gasket

Claims

1. a case having a concave container having a bottom and a side wall and a lid covering an opening of the concave container; a power generating element housed in the case, the power generating element including a laminate including a first electrode layer, a second electrode layer, and a solid electrolyte layer disposed between the first electrode layer and the second electrode layer; a conductive plate disposed between the power generating element and the lid; an elastic insulator disposed between the conductive plate and the lid, the conductive plate has a support portion for supporting the conductive plate at a position corresponding to an upper end surface of a side wall portion of the concave container, the support portion is a protrusion formed by protruding a part of the conductive plate toward an upper end surface of a side wall portion of the recessed container, The elastic insulator presses the conductive plate toward the power generating element when the battery is housed in the case.

2. 10. The battery of claim 1, The conductive plate has at least two or more supports.

3. 10. The battery of claim 1, The conductive plate has a flat surface facing the power generating element.

4. 10. The battery of claim 1, The battery, wherein the elastic insulator is made of rubber.

5. The battery according to any one of claims 1 to 4, The battery further comprises a conductive sheet disposed between the conductive plate and the power generating element.

6. a case having a concave container having a bottom and a side wall and a lid covering an opening of the concave container; a flat battery housed in the case; a conductive plate disposed between the flat battery and the lid; an elastic insulator disposed between the conductive plate and the lid, the conductive plate has a support portion for supporting the conductive plate at a position corresponding to an upper end surface of a side wall portion of the concave container, the support portion is a protrusion formed by protruding a part of the conductive plate toward an upper end surface of a side wall portion of the recessed container, The elastic insulator presses the conductive plate toward the flat battery when housed in the case.

7. 7. The battery of claim 6, The conductive plate has a flat surface facing the flat battery.

Citation Information

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